Wireless-telegraph receiver.



No. 801,118. I PATENTED 001?. 3,1905.

I G. T. SWENSON.

WIRELESS TELEGRAPH RECEIVER.

APPLICATION FILED D160. 1, 1902.

2 SHEETS-SHEET l No. 801,118. PATENTED OCT. 3,1905.

G. T. SWBNSON.

I WIRELESS TELEGRAPH RECEIVER.

APPLICATION FILED D301, 1902.

2 SHEETB-SHEET 2.

UNITED STATES PATENT oEEIoE.

GUSTAF T. SWVENSON, OF NEAR SAN PEDRO. CALIFORNIA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO PACIFIC \VIRELESS TELEGRAPH COMPANY, A CORPORATION OF IVASl-IINGTON.

WIRELESS-TELEGRAPH RECEIVER.

Specification of Letters Patent.

Patented Oct. 3, 1905.

Application filed December 1, 1902. Serial No. 133,514.

To all whom it may concern.-

Be it known that I, GUSTAF T. SWENSON, a citizen of the United States, residing near San Pedro, in the county of Los Angeles and State of California, have invented new and useful Improvements in Wireless Telegraph Receivers, of which the following is a specification.

My invention relates to instruments de- I O signed for receiving telegraph-messages by the system denominated wireless telegraphy; and the object thereof is to produce a simple device which will be operative in all positions and when used in conjunction with a telephone- 5 receiver or other electrically-Opel"ated soundproducing instrument will produce therein audible impulses which can be readily understood by the operator and which may be used with a telegraphic receiving instrument.

The accompanying drawings, which are diagrammatic representations, illustrate my invention as used in conjunction with a telephone-receiver.

Figure l is a diagrammatic view of the 5 whole apparatus. Figs. 2 and 3 are like diagrammatic views with some of the parts enlarged. Fig. 4 shows a modification of the contact between the stationary and moving parts.

In the drawings A is a telephone-receiver which is electrically connected by wire B to one pole of battery C and by wire D with ground E or other suitable capacity. The other pole of the battery is electrically con- 35 nected by Wire F to a metallic contact-strip G secured to an insulating-block H, which block is secured to the frame I of a train of wheels J. In the axle K of the outer or slowest-moving wheel J of this train is a socket 4 K in which is mounted a small rod L of polished steel or iron which I will call the coherer-rod. It is movable in the socket and is held in any desired position therein by thumb-screw M or by any other suitable 5 means. This train of wheels may be operated by any suitable means which will impart an exceedingly-slow rotary movement to said coherer-rod. I have shown an electric motor N for that purpose as it imparts a continuous 5 motion which I consider is the best motion.

Passing through a threaded hole in contactstrip Or is a' metallic thumb-screw O having a central socket, (shown in dotted lines,) in

which is longitudinally movable a small metallic rod P to which is centrally secured a carbon filament R which is preferably the size of an incandescent siXteen-candle-power-light carbon. This filament is held pressed against the coherer-rod by pad S affiXed to spring T which spring is affixed to rod P thereby preventing any vibratory movement of the filament. By preventing the filament from vibrating all danger is avoided of interfering with the proper flow of the current. hen the filament is not thus spring-pressed the vibration thereof often interferes with the flow of the current to such an extent that dashes become dots and the message cannot be properly understood. Rod P is adjustably secured in the socket by the thumb-screw U. The aerial conductor or mast-wire V is electrically connected to wire F; and the frame I is electrically connected by wire with the ground E or other capacity. In the operation of my device when the telephone-receiver is at the ear of the operator a feeble current flows through the circuit. hen the aerial conductor receives the I-Iertzian waves of the sending instrument more complete contact or cohesion takes place between the carbon fila ment and the coherer-rod and more current flows from the battery, thereby producing a greater sound in the telephone-receiver, and thereby rendering the electric signals sent by the sending instrument distinctly audible to the operator. The continuous rotation of the cohcrer-rod, slight as it is, destroys at each interruption of the Hertzian wave the cohesion between the carbon filament and the coherer-rod. If desired the coherer-rod could be made of carbon and the filament replaced by a metallic wire of like capacity, as it is immaterial which part is carbon and which metal. I have also found by experiment that sound is audible in the telephone-receiver when the parts are all metallic but the sound produced is not nearly as distinct as when one of the parts is carbon and the other metal.

In the practical working of my device I have found that a coherer-rod of iron three thirtyseconds of an inch in diameter which is caused to revolve once an hour and a carbon filament taken from a siXteen-candle-power incandescent-electric-light lamp produced very satisfactory results. I have also found in practice that it is better to change occasionally the engaging surfaces between the carbon filament and the coherer-rod. I am able to make many such changes by reason of the longitudinal movement of the coherer-rod in its socket and the vertical adjustment of the carbon filament. If desired a metallic disk X could be mounted on the end of the shaft on which Wheel J is mounted and the carbon filament held in contact With the disk X.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is-

In a system of Wireless telcgraphy having l l l 

